After a nearly two year long battle, the U.S. Patent and Trademark Office has decided that Microsoft's two patents on the FAT file system are in fact valid. Last October the U.S. Patent and Trademark Office rejected two Microsoft patents over the popularly used FAT file format. This came after a re-examination of Microsoft's patents sought by the Public Patent Foundation. The Public Patent Foundation argued that others had done similar file format work before Microsoft's patent, and that awarding Microsoft this patent would only hurt the computer community.

Now that the re-examination is over, the Patent Office has concluded that Microsoft's FAT file system is in fact novel. This decision now means that the two FAT file system patents Microsoft submitted can become patentable. While this is in fact very good news for Microsoft, others in the computer industry are not so pleased with this decision. Who could blame them? After all last October Microsoft published an outlined version of its FAT file system license, with prices ranging from cameras to standard televisions.

The FAT file system is used not only on versions of the Windows operating system, but also on removable flash memory cards, Linux/Unix products, and is a common file system used to transfer data with Windows. The Public Patent Foundation is sure to fight back, but with the patent almost handed to Microsoft they may already be out of time.